Field of the Invention
The present invention relates to an organic light emitting display capable of reducing deterioration speed of a pixel.
Description of the Related Art
An organic light emitting diode (OLED) emits light by a difference in energy in a process where holes injected through an anode electrode and electrons injected through a cathode electrode are recombined in an organic light emitting layer. At this time, the emitted light may have different wavelengths, for example, red, green, and blue wavelengths in accordance with the organic light emitting layer. The wavelength of the emitted light is determined by a material (including host material and a dopant material) of the organic light emitting layer.
Since a characteristic of a part of the material of the organic light emitting layer is deteriorated in accordance with atmosphere and emission time, brightness of the light emitted from the OLED is gradually reduced. For example, meanwhile a brightness reduction ratio of an organic light emitting layer that emits light of green wavelength in accordance with time is relatively small, as brightness is rapidly reduced after a time in an organic light emitting layer that emits light of green wavelength. Therefore, due to a difference in the brightness reduction ratio caused by a difference in the characteristics of the materials, a difference in brightness is generated between OLEDs.
In addition, when the same image such as a logo, a time, and subtitles of a broadcaster is continuously displayed at a specific position, deterioration of the OLEDs may be accelerated. Due to deterioration caused by a long-time operation, an afterimage or image sticking may be generated. A spot caused by the afterimage may deteriorate picture quality.